As mentioned in The Role of Devils, there are 45 families, organized into 5 territories. Most families are named for the arch-devil that occupies the role of Don; exceptions include the Grigori and the Hinn. The territories and their constituent families are described below.

Thoraz

They mainly work for the angels; only the weaker ranks interact with mortals. Heavily involved in elemental planes. Politically conservative. Based in the Machinarium of the Celestial City.

Families

  •  Ala (NE): Known for driving hard bargains. Greedy, he works his subordinates hard and rewards ambition, as long as that ambition doesn't threaten him.
  •  Barong (NG): Associated with lions; her Family specializes in anti-demon operations.
  •  Charun (LN): Dour and quiet, specializes in anti-undead operations
  •  Culsu (N): Known as the Doorwarden, this Family controls passage from the mortal plane into Shadow.
  •  Grigori (N): This family specializes in scrying and spying on creatures. Led by an imp whose desire for information has given him lots of blackmail material. Unlike most of the territory, they're neutral like arms-dealers are neutral--they supply both sides with information.
  •  Malphas (LN): This family specializes in construction and is dominantly involved in maintenance of the Celestial City. Only rarely summoned to the mortal plane.
  •  Marchosias (LG): Judge of fair battles and duels. Considered stick-in-the-muds by others.
  •  Pelesit (N): Specializes in defensive operations, provides combat troops for mortal-plane operations.
  •  Valac (CN): Finder of Treasures (even other people's treasures). Experts at scrying for objects.

Mara-deva

Many succubi/incubi. 2nd-most-commonly summoned. Corruption/seduction/deception over brute force. Politically progressive. Based in Mara.

Families

  •  Akvan (CN): Foremost fashion experts in the Astral Plane, for when you need to look devilishly good.
  •  Abyoza (CE): Often summoned to track down rivals or to lay curses on adulterous spouses. Also summoned to engineer the fall of political or economic rivals.
  •  Bakasura (LE): The most militant of the Mara-deva families, Bakasura is there for you when you need your enemies crushed with style.
  •  Drekavac (NE): When you need someone scared to death (literally or figuratively), Drekavac has a nice installment plan that will fit any soul's budget.
  •  Forneus (LE): Spin-meisters supreme. If you need someone to write a great speech (especially if the raw truth won't work), they're your devils.
  •  Ipos (NG): An Ipos imp on your shoulder will feed you all the right lines to cut your sparring partner down to size and the courage to deliver them. The courage tends to be that of the wine-cup, however.
  •  Lempo (CG): A two-edged sword--romance is their forte, but so is rather unpredictable behavior. You may end up proposing to the wrong sister (or their cow!) if you fall under Lempo's influence.
  •  Pruflas (CE): When there's nothing you like more than causing a ruckus, Pruflas has you covered. Ranging from practical jokes to impersonations designed to make your target see red, provocation is their wheelhouse.
  •  Shax (CE): Need something that isn't yours? Call Shax. Keep a firm grasp on your soul, or they'll steal that too.

Chou

Most often called for combat. Straight-forward and brutal. Respect strength. Politically conservative. Not fond of mortals (or anything they consider weak). Based in Ghenna.

Families

  •  Aeshema (CE): Kill! Crush! Rage against chains!
  •  Angra Manyu (CE): All that exists must be destroyed. All returns to non-existence, to be reborn. 
  •  Aseg (LE): The stones of the earth are my army; all foes will break against their bulwark. Beauty is for those weak fools in Mara-deva. Our looks are another weapon.
  •  Gualichu (NE): What I have, I keep. That includes the bodies I possess. Like a puppet master, I manipulate them all.
  •  Hinn (N): Cry havoc and let slip the (flaming) dogs of war! Who's a good hell-hound? You're a good hell-hound. 
  •  Kroni (CE): Kill, kill, kill, annihilate, kill...
  •  Kumbhakarna (LN): Come! Let us test our might against each other.
  •  O Tokata (NE): The dead do not lie quiet. As soon you will know when you join them.
  •  Zagan (LE): I am the only king! All will bend the knee to my majesty!

Leiutis

Least warlike, most likely to form familiar pacts or Warlock pacts. Frequent users of blackmail. Politically progressive. Based in Aaru. Smallest territory in numbers.

Families

  •  Abraxas (LN): Want to know about the planes beyond the Material? We can help with that...for a price, of course.
  •  Allocer (N): The arcane arts are our stock in trade. What do you want to know? It's all available, if you can pay the price, of course.
  •  Beleth (CG): The harmonies of the celestial spheres will flow into you...once the golden ring of your anima sounds in our ears.
  •  Danjal (CN): Need someone taught a skill? Taught how to fight? We provide drill masters. Bulk rates available!
  •  Orobas (CN): The truth is out there...and we can find it for you.
  •  Phenex (NE): We make sure that the truth isn't out there, even against Orobas.
  •  Puloman (N): What happens when you mix this and that? We can tell you before you blow your fingers off!
  •  Ravan (N): Want to know how to appease that angry deity or kami? Need to know the right prayers to activate that temple? Call Puloman!
  •  Ukobach (N): All the best recipes, all in one place. Subscription plans available, cheap!

Ka-Kola

Not cohesive. Each family is independent. Wide variation. Politics as marked. Based in Naga Padoha, but present all over.

Families

  •  Anzu (CN): The Mother of Monsters aids those that create monsters in Her name. Unaligned (apathetic)
  •  Arunasura (CE): Those that fight the gods are our allies. Unaligned (kill them all)
  •  Bukavac (N): Ours is the azure watch, over oceans and those that live within. Unaligned (apathetic)
  •  Boruta (N): We guard the green forests; the trees are our sheep. Unaligned/Conservative
  •  Dzoavits (CN): Burn! Burn in the fires of the deep earth! Raise up islands and mountains! Unaligned (kill them all)
  •  Leyak (CN): We guard all those whose ancestors were of the Races of Man, yet are created at the hands of the Races of Man. Progressive
  •  Namtar (N): Disease and medicine are opposite sides of the same coin; one without the other does not exist. Progressive
  •  Surgat (CN): All that is closed must be opened/as soon as Culu closes a door, we open a window. Conservative
  •  Toyol (NE): Who better to break that curse than the ones who laid it? Progressive